A good question.
A local answer.

Map each candidate hotel's walk to dining, transit and the activities you will actually do.

Check cafés, toilets and the walk back to your bus stop before settling in.

Choose one beach per outing if transfers make a combined day too long.

Compare door-to-door time and shade for both options, and plan the return before the child is tired.

Arrange a non-drinking driver and ask about outdoor space or shade, especially if the children are likely to need a break.

Pick your destination within Kings Park first, then use the current public transport planner for that entrance.

Expect downhill and an uphill return if you walk both ways, and check the crossing and footpath near the boat house.

Mark two or three beaches or lookouts that matter most, and verify the last bus from each before getting off.

Choose a few stops with time to walk and enjoy them, rather than trying to circle the whole island.

Compare what's in season and the price per quantity on the day; no market is consistently cheaper than every supermarket.

Choose by the produce or prepared food you want, then check the market's current day, location and stall list.

Confirm luggage rules and the final connection back to your accommodation before choosing the route.